The present disclosure relates generally to a multi-dimensional barcode and, more particularly, to a method of, and a system for, electro-optically reading the barcode by image capture, and, still more particularly, for authenticating and/or identifying an object associated with the barcode, and/or for storing information relating to the barcode and/or to an object associated with the barcode.
Barcode scanning technology has greatly impacted the lives of consumers and has increased the efficiency of many businesses and organizations, such as supermarkets, department stores, factories, the military, the health industry, the insurance industry, and the like, worldwide. Barcode scanning technology is relatively inexpensive to implement and automatically correlates physical objects to information systems. Just like a human can be identified by a name, a barcode gives a name to any object and allows automatic capture of that name through various scanning devices, also known as scanners or readers. The readers may detect return laser light scanned across the barcode, or may capture return light from the barcode as an image. The return light is processed by computerized information systems where decisions may be made regarding each object, such as its price, manufacturer, date of manufacture, distribution chain, inventory level, etc.
Object identification data may be encoded as a series of elements of different light reflectivity printed on a label. The elements are spaced apart widthwise of the label along a horizontal direction to form a one-dimensional (1D) barcode or symbol. The elements may be configured as rectangular bars having variable widths and spaced apart from one another to form other elements, i.e., spaces, which also have variable widths. The heights of the bars and spaces in the 1D barcode, as considered along a vertical direction heightwise of the label, carries no information. The printed bars are typically colored with a foreground color, typically black, while the spaces are colored with a contrasting background color, typically white. The particular layout of the bars and spaces, as well as the sizes of the widths of the bars and spaces, describe one of many different schemes or symbologies in which the identification data is encoded and decoded.
To encode additional information, a plurality of 1D barcodes may be stacked along the vertical direction, or a combination of the elements may be arranged along both the horizontal and vertical directions, to encode the additional information to form a two-dimensional (2D) barcode or symbol. To encode still more information, it is known to configure the elements with three dimensions, such as particles, that are raised relative to the label and can, for example, be tactilely felt when touched. The variable depths of the particles, as considered in a direction perpendicular to the label, form a three-dimensional (3D) barcode or symbol. It is possible to encode still more information by forming a four-dimensional (4D) barcode or symbol in which the particles exhibit characteristic colors that can be contrasted with the background color, or from the label, and/or from the object to which the particles have been applied.
In order to capture depth information in photography, it is known to capture two images from different horizontal positions to obtain a stereoscopic image pair. This can be done by utilizing two separate side-by-side cameras, or by moving one camera from one position to another between image exposures, or by incorporating two or more side-by-side lenses in a stereo camera. It is also known to use a camera in a smartphone, or a stand-alone camera, to capture 3D models of real-world objects by simply moving the camera around the object of interest and by capturing several images with the camera.
However, such known depth capture techniques have not always proven to be altogether satisfactory, because the relatively small depths of the raised 3D particles are difficult to accurately resolve. Also, such known depth capture techniques cannot be performed at the relatively fast speed that is needed to capture a barcode in many commercial applications. For example, when objects and packages are moving quickly on a conveyor belt or along a supply chain, the speed of image capture and decoding the depth information in the barcode is critically important. While it may be acceptable for a typical consumer to move an image capture device relative to a multi-dimensional barcode, it is not a viable option in the real-world to simply move the image capture device around the object of interest to capture several images in supply chain applications.
Hence, as satisfactory as such multi-dimensional barcodes have been in storing information, it is desired to still further increase the amount of information encoded therein, without compromising the ability to accurately and rapidly decode the encoded information, especially in commercial applications. Accordingly, it is desired to increase the capacity or density of information encoded in a multi-dimensional barcode, and to more accurately and rapidly decode the encoded information therein.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention.
The system and method have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.